Movable form for dams or the like



June 13, 1939. D, E 2,162,220

MOVABLE FORM FOR DAMS OR THE LIKE Filed Oct. 22, 1938 2 She ets-SheeblINVENTOR John D. Jess en June 13, 1939. .1. D. JESSEN MOVABLE FORM FORDAMS OR TH E LIKE Filed Oct. 22, 1938 2 Sheets-Sheet 2 I I I I I I I IIII Patented June 13, 1939 UNITED STATES PATENT OFFICE MOVABLE FORM FORDAMS OR THE LIKE Application October 22, 1938, Serial No. 236,503

7 Claims.

This invention relates to a form for making poured concrete structuresor the like, and, in particular to a form for the construction ofinclined walls such as the deck slabs of a dam of the Ambursen type.

Considerable ,difiiculty has been experienced heretofore in handling theform for the lower face of an inclined wall or slab section,particularly when the slab is to be cast at considerable heights abovethe ground level as in the case of dam construction. The difiicultyencountered resides largely in the fact that after the casting of a slabsection, the form for the lower face thereof is supported beneath thefinished section in a position somewhat inaccessible to workmen on theupper face of the slab. I have invented a novel form and method ofhandling it which entirely obviate the difliculties encounteredheretofore and greatly simplify the movement of a form from one of itssuccessive positions to the next as the slab sections are cast.

A preferred embodiment of the invention comprises a form panel extendingbetween spaced buttresses on which the finished slabs rest. Framingmembers supporting the panel extend upwardly thereabove to a cross beamadapted to travel up the inclined faces of two adjacent buttresses. Acounterbalance secured to the panel is effective to hold the latter ininclined position when the lower portion is freed from a completed slabsection and the entire panel is suspended from the cross beam fortraveling movement upwardly along the buttresses. This embodiment of theinvention and a preferred method of utilizing it will be described indetail herebelow with reference to the accompanying drawings. In thedrawings: i

Fig. 1 is a sectional view taken through the form of my invention alongthe plane midway between adjacent buttresses and parallel thereto;

Fig. 2 is a sectional view taken substantially along lines IIII of Fig.1;

Fig. 3 is a View partly in section, partly in elevation, takensubstantially along lines III-III of Fig. 1 and showing the form for thelower face of the slab; and

Fig. 4 is a partial elevation such as might be projected from Fig. 1onto the plane indicated by the lines IV-IV thereof.

Referring now in detail to the drawings, a dam of the Ambursen typecomprises spaced buttresses l8 and H of triangular form having inclinedfaces 12 and laterally projecting shoulders or faces l3. Deck slabs l4extend between the buttresses, being cast in place upon the faces I3.

The slabs M are cast by the aid of a slip form indicated generally at I5and comprising upper and lower panels/l6 and H.

The upper panel l6 comprises cross beams I8 bridging the space betweenadjacent buttresses and provided with wheels l9 adapted to travel up thefaces 12 of the buttresses. Stringers 28 are secured to the beams [8 atright angles thereto and support a form plate 2|. Trusses 22 are securedto the beams 18 to resist deflection thereof. The entire form is held inposition on the inclined faces of the buttresses by cleats 23 secured byanchor bolts 24 to the buttresses.

The bottom form or panel I! is composed of cross beams 25 to whichstringers 26 extending at right angles thereto are secured. A form plate2? is carried on the stringers 26. The form I! includes adjustable sidesections 28 capable of movement inwardly or outwardly along the beams 25to compensate for minor variations in the side faces of the buttresses.

Tie rods 29 extend between the panel l6 and the panel 11. Each rod iscomposed of a middle section 30, an upper section 3!, and a lowersection 32. The several sections are connected by cone nuts 33. Asillustrated, the tie rods are provided with holding nuts which bear oncross plates extending between the members comprising the beams l8 and25.

, As best shown in Fig. 3, the stringers 26 forming part of the panel I!extend upwardly above the upper edge of the form plate 21. The upperends of these stringers are secured to a cross beam 34 extending betweenadjacent buttresses and provided with wheels 35 adapted to travelupwardly along the inclined shoulders or lateral faces l3 thereof. Thebeam 34 with its wheels 35 provides a pivotal support for the panel I!when the latter is freed for movement upwardly along the buttresses.

A counter-balancing frame comprises members 36 extending downwardly andoutwardly, and beams 3l extending outwardly from opposite ends of thestringers 25. The outward ends of the members 36 and the beams 31 arerigidly connected and a counter-balance 38 is disposed on the supportingframework thus provided. Planking may also be laid across the beam 31 asshown at 35: to provide a working platform below the panel H. Thecounter-weight 38 is so designed as to hold the panel 11 in inclinedposition when the latter is free from the adjacent deck slab and issupported exclusively from the cross beam 34. The weights of the variousparts are preferably such that, when so suspended, the panel ll swingsslightly away from the lower surface of the previously cast slabsection.

The method of employing the invention will now be explained, assumingthat the parts are in the position shown in Fig. 1 and that the slab l4shown in the lower portion thereof has already been cast. With the partsin the positions shown, concrete is poured between the panels [6 and Hto form a slab section, the upper edge of which is indicated at M. Asshown in Fig. l, the abutting surfaces of adjacent slab sections arealternately horizontal and normal to the lateral faces of the slabs.When the slab section M has been completed, the tie rod sections 3| areunscrewed from the cone nuts 33 which, with the rod sections 36, remainembedded in the slab section. The panel l6 together with its supportingbeams and trusses may then be hoisted upwardly along the buttresses, thewheels l9 traveling along the faces [2 thereof. When the panel I6 hasbeen raised into position for casting the next slab, the cleats 23 arerelocated to hold the panel in its advanced position. The rod sections32 are then unscrewed from the cone nuts 33 embedded in the lower faceof the slab section [4. This leaves the panel l1, its supportingframework and the counter-balance suspended solely from the cross beam34. Limited tilting movement of the latter is permitted on the axles ofthe wheels 35. As stated, the counterbalance is of such weight relativeto the other parts of the panel I! that the whole structure swingsslightly away from the under surface of the slab M. The beam 34 may thenbe hoisted by suitable cables so that it and the entire form 1 structuretravels upwardly along the faces [3 of the buttresses, the wheels 35rolling thereon. When the panel H has been raised to the proper positionfor the casting of the next succeeding slab, the tie bolt sections 3|and 32 are connected (1)] by new cone nuts 33 and central rod sections30 and the entire form is then ready for a further pouring operation.The cycle described is re peated until all the sections of the deckslabs between two adjacent buttresses have been completed.

The procedure described above may be reversed to advantage, 1. e., panelI1 may be moved first and panel l6 afterwards. Thislatter methodrequires that panel ll be held, after being raised,

by means of cables or otherwise, pending the subsequent raising of panelHi.

It will be apparent from the foregoing description that the inventionprovides a novel form of construction which can readily be moved fromone position to another in the pouring of successive slab sections. Themovement of the bottom panel I! away from the lower surface of thepreviously cast section is just sufficient to provide easy clearance.The movement of the form from pouring to transporting position is thusrelatively slight. While the construction of the bottom panel or formaccording to the invention is relatively simple and inexpensive, asubstantial advantage is derived therefrom in the ease and readinesswith which the panel may be advanced upwardly along the buttresses. Thesaving in the time required for advancing the form, which is madepossible by the invention, greatly expedites the erection of structureshaving inclined walls such as the deck slabs of an Ambursen type dam.

While the invention has been described herein with particular referenceto the latter, it may also be employed on other structures where similarproblems are encountered.

Although I have illustrated here but a pre ferred embodiment of theinvention, changes in the structure and procedure disclosed may be madewithout departing from the spirit of the invention or the scope of theappended claims.

I claim:

1. A form for the casting of a slab extending between spaced buttressesand resting on inclined faces thereof comprising a panel adapted toextend between said buttresses, a beam extending between said buttressesadjacent the upper edge of the panel, said panel being secured to thebeam, and a counterbalance adapted to hold said panel substantially inits normal inclined position when suspended from said beam.

2. A form for the casting of a slab extending between spaced buttressesand resting on inclined faces thereof comprising a panel adapted toextend between said buttresses, means adjacent the upper edge of saidpanel adapted to engage said faces to support the panel thereon, and acounter-balance effective to hold said panel substantially in its normalposition when supported exclusively by said means.

3. A form for the casting of successive slab sections resting on theinclined faces of spaced butresses, said form comprising a panel adaptedto extend between said buttresses, means adjacent the upper edge of saidpanel adapted to engage said buttresses for supporting said panelthereon, and a counter-balance effective to hold said panelsubstantially in its normal, inclined position when freely suspendedfrom said means.

4. Supporting means for an inclined form on which are cast successiveslab sections resting on inclined faces of spaced buttresses, said meanscomprising a suspension adjacent the upper edge of the form adapted toengage said buttresses, and a counter-balance effective to hold saidform in inclined position when it swings freely on said suspension.

5. A form for the casting of successive slab sections resting on theinclined faces of spaced buttresses, said form comprising a paneladapted to extend between said buttresses, stringers extending beyondsaid panel, a cross beam adapted to be tiltably supported on said facesto which said stringers are secured, and a counter-balance holding saidpanel in inclined position when swinging freely from said beam.

6. A form for the casting of successive slab sections resting on theinclined faces of spaced buttresses, said form comprising a paneladapted to extend between said buttresses, stringers extending beyondsaid panel, a cross beam having wheels thereon adapted to travel alongsaid faces, said stringers being secured to said beam, and acounter-balance holding said panel in inclined position when swingingfreely from said beam.

7. A form for the casting of an inclined slab extending between spacedbuttresses, said form comprising a panel adapted to extend between saidbuttresses and a framework carrying a counterweight so disposed that theform when suspended will remain in inclined position.

JOHN D. JESSEN.

